Method and apparatus for image forming capable of effectively performing an image fixing process

Abstract

A fixing apparatus includes a fixing roller, a heat roller, a seamless fixing belt, a pressure roller, a supporting roller, and a pressure applying member. The heat roller includes a fixing heat source. The seamless fixing belt is extended between the fixing roller and the heat roller. The pressure roller pushes the fixing roller via the fixing belt to form a second fixing-process area. The supporting roller contacts inside the fixing belt and winds the fixing belt around a surface of the pressure roller to form a first fixing-process area upstream of and next to the second fixing-process area. The pressure applying member applies a pressure to the heat roller in a direction opposite to an ejection of the recording sheet from the second fixing-process area to adjust a fixing pressure of the first fixing-process area.

1. A fixing apparatus, comprising:
 a receiving roller configured to rotate around a rotation axis fixed at a position;  
 a fixing roller configured to apply a pressure to said receiving roller so that a fixing nip area is formed between said fixing roller and said receiving roller, said fixing roller having an elastic layer;  
 a heat source provided within said fixing roller and adapted to apply heat to a recording sheet carrying an image on a surface thereof; and  
 a driving source configured to rotate at least one of said fixing roller and said receiving roller,  
 wherein the recording sheet is conveyed to said fixing nip area in an orientation in which the surface carrying the image faces said fixing roller and another surface of the recording sheet carrying no image faces said receiving roller,  
 wherein said receiving roller comprises a hard-metal core and a high-release elastic layer covering said hard-metal core, and  
 wherein said high-release elastic layer has a thickness of at most 200 μm.  
 
   
   
     2. A fixing apparatus as defined in  claim 1 , wherein said receiving roller has a structure resistant to deformation in comparison with a structure of said fixing roller, and the recording sheet is guided at a leading edge thereof by a surface of said receiving roller to enter said fixing nip area. 
   
   
     3. A fixing apparatus as defined in  claim 1 , wherein said receiving roller is rotated by said driving source and said fixing roller is rotated due to contact with said receiving roller. 
   
   
     4. A fixing apparatus as defined in  1 , further comprising a pressure applying member configured to apply a pressure to said fixing roller so that said fixing roller pushes said receiving roller. 
   
   
     5. A fixing apparatus as defined in  claim 4 , further comprising a stopper configured to stop at a predetermined position said fixing roller from being moved towards said receiving roller by said pressure applying member. 
   
   
     6. A fixing method, comprising the steps of:
 fixing at a position a rotation axis of a receiving roller having a deformation-resistant structure, said receiving roller including a hard-metal core and a high-release elastic layer covering said hard-metal core, and said high-release elastic layer having a thickness of at most 200 μm;  
 applying a pressure to a fixing roller to push said receiving roller so that a fixing nip area is formed between said fixing roller and said receiving roller;  
 rotating said receiving roller such that said fixing roller follows in rotation;  
 conveying a recording sheet carrying an image on a surface thereof into said fixing nip area in an orientation in which said surface carrying said image faces said fixing roller and another surface of said recording sheet carrying no image faces said receiving roller; and  
 performing a fixing process using said fixing roller to apply heat and pressure to said recording sheet.  
 
   
   
     7. A fixing method, comprising the steps of:
 fixing at a position a rotation axis of a receiving roller having a deformation-resistant structure, said receiving roller including a hard-metal core and a high-release elastic layer covering said hard-metal core, and said high-release elastic layer having a thickness of at most 200 μm;  
 applying a pressure to a fixing roller and a fixing belt wound around a surface of said fixing roller to push said receiving roller so that a fixing nip area is formed between said fixing roller and said fixing belt;  
 rotating said receiving roller such that said fixing roller follows in rotation;  
 conveying a recording sheet carrying an image on a surface thereof into said fixing nip area in an orientation in which said surface carrying said image contacts said fixing belt and another surface of said recording sheet carrying no image contacts said receiving roller; and  
 performing a fixing process using said fixing roller to apply heat and pressure to said recording sheet.  
 
   
   
     8. A fixing method as defined in  claim 7 , further comprising the steps of:
 providing at least two supporting rollers inside said fixing belt to support said fixing belt together with said fixing roller;  
 unifying said at least two supporting rollers, said fixing roller, and said fixing belt into one fixing unit;  
 holding said fixing unit for a turning movement about a rotation axis of one of said at least two supporting rollers, located upstream from said fixing nip area in a direction of transferring said recording sheet; and  
 turning said fixing unit to apply said pressure to said fixing roller.  
 
   
   
     9. An image forming apparatus, comprising:
 an image forming station adapted to form an image on a recording sheet;  
 a sheet transfer mechanism adapted to transfer the recording sheet carrying an image on a surface thereof; and  
 a fixing station configured to perform a fixing process with heat and pressure, said fixing station comprising: 
 a receiving roller configured to rotate around a rotation axis fixed at a position and to receive the recording sheet carrying an image on a surface thereof;  
 a fixing roller configured to apply a pressure to said receiving roller so that a fixing nip area is formed between said fixing roller and said receiving roller, said fixing roller having an elastic layer;  
 a heat source provided within said fixing roller and configured to apply heat to the recording sheet;  
 a driving source configured to rotate at least one of said fixing roller and said receiving roller,  
 wherein the recording sheet is conveyed to said fixing nip area in an orientation in which the surface of the recording sheet carrying the image faces said fixing roller and another surface of the recording sheet carrying no image faces said receiving roller,  
 wherein said receiving roller comprises a hard-metal core and a high-release elastic layer covering said hard-metal core, and  
 wherein said high-release elastic layer has a thickness of at most 200 μm.  
 
 
   
   
     10. An image forming apparatus as defined in  claim 9 , wherein said receiving roller has a structure resistant to deformation in comparison with a structure of said fixing roller, and wherein the recording sheet is guided at a leading edge thereof by a surface of said receiving roller to enter said fixing nip area. 
   
   
     11. An image forming apparatus as defined in  claim 10 , wherein said receiving roller is rotated by said driving source and said fixing roller follows a rotation of said receiving roller. 
   
   
     12. An image forming apparatus as defined in  claim 9 , further comprising a pressure applying member configured to apply a pressure to said fixing roller so that said fixing roller pushes said receiving roller. 
   
   
     13. An image forming apparatus as defined in  claim 12 , further comprising a stopper configured to stop at a predetermined position said fixing roller from being moved towards said receiving roller by said pressure applying member.